cc: Add image decode queue functionality to image manager.

cc/trees/layer_tree_host_in_process.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_IN_PROCESS_H_
 #define CC_TREES_LAYER_TREE_HOST_IN_PROCESS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 56 matching lines @@
 class CC_EXPORT LayerTreeHostInProcess : public LayerTreeHost {
  public:
   // TODO(sad): InitParams should be a movable type so that it can be
   // std::move()d to the Create* functions.
   struct CC_EXPORT InitParams {
     LayerTreeHostClient* client = nullptr;
     TaskGraphRunner* task_graph_runner = nullptr;
     LayerTreeSettings const* settings = nullptr;
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner;
     ImageSerializationProcessor* image_serialization_processor = nullptr;
-    MutatorHost* mutator_host;
+    MutatorHost* mutator_host = nullptr;
+    scoped_refptr<base::SequencedTaskRunner> image_worker_task_runner;
 
     InitParams();
     ~InitParams();
   };
 
   static std::unique_ptr<LayerTreeHostInProcess> CreateThreaded(
       scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
       InitParams* params);
 
   static std::unique_ptr<LayerTreeHostInProcess> CreateSingleThreaded(
@@ skipping 222 matching lines @@
 
   // The state that was expected to be reflected from the main thread during
   // BeginMainFrame, but could not be done. The client provides these deltas
   // to use during the commit instead of applying them at that point because
   // its necessary for these deltas to be applied *after* PropertyTrees are
   // built/updated on the main thread.
   // TODO(khushalsagar): Investigate removing this after SPV2, since then we
   // should get these PropertyTrees directly from blink?
   std::unique_ptr<ReflectedMainFrameState> reflected_main_frame_state_;
 
+  scoped_refptr<base::SequencedTaskRunner> image_worker_task_runner_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostInProcess);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IN_PROCESS_H_